Awesome REST 
A collaborative list of great resources about RESTful API architecture, development, test, and performance. Feel free to contribute to this on-going list.
- Design
- Guidelines
- Standards
- Clients
- PHP
- Client-side JavaScript
- Node.js
- Ruby
- Go
- .Net
- Generators
- Servers
- Directly On Top Of A RMDB
- Node.js
- PHP
- Symfony2
- Python
- Ruby
- Go
- Java
- Haskell
- Testing
- Querying
- Mocking
- Public REST APIs To Use In Tests
- Documentation
- API Gateway
- SaaS Tools
- Miscellaneous
Design
- Architectural Styles and the Design of Network-based Software Architectures - Roy Fielding's dissertation defining REST
- HTTP API design guide extracted from work on the Heroku Platform API
- Best Practices for Designing a Pragmatic RESTful API
- How to design a REST API? - Full guide tackling security, pagination, filtering, versioning, partial answers, CORS, etc.
- Richardson Maturity Model - Explained by Martin Fowler, originally presented by Leonard Richardson at the QCon 2008.
- Enterprise Integration Using REST - Discusses the constraints and flexibility that you have with nonpublic APIs, and lessons learned from doing large scale RESTful integration across multiple teams.
- HATEOAS - Clear explanation on what HATEOAS is, and why you should use it.
- How to GET a cup of coffee
- REST API Tutorial - RestApiTutorial.com is dedicated to tracking REST API best practices and making resources available to enable quick reference and self education for the development crafts-person.
- API-Security-Checklist - Best practices about REST API security
Guidelines
- Adidas REST API Guidelines - Adidas REST API Guidelines define standards and guidelines for building REST APIs at adidas.
- Atlassian REST API design guidelines version 1 - This document provides guidelines to Atlassian developers who are designing REST APIs for Atlassian applications.
- Cisco REST API Guide - Guidelines for designing REST APIs at Cisco.
- Google Cloud API design guide - Guidelines Google follows when designing Cloud APIs and other Google APIs (REST APIs and gRPC APIs).
- Haufe API Style Guide - Guidelines created by Haufe-Lexware CTO team.
- Microsoft REST API Guidelines - The Microsoft REST API Guidelines, as a design principle, encourages application developers to have resources accessible to them via a RESTful HTTP interface.
- Restful API Guidelines by Zalando - Developing Restful APIs: A Comprehensive Set of Guidelines.
Standards
- JSON API - Standard for building APIs in JSON.
- RAML - Simple and succinct way to describe RESTful API.
- JSend - Simple specification that lays down some rules for how JSON responses from web servers should be formatted.
- OData - Open protocol to allow the creation and consumption of queryable and interoperable RESTful APIs. Quite complex.
- HAL - Simple format that gives a consistent and easy way to hyperlink between resources in your API.
- JSON-LD - Standard for describing Linked Data and hypermedia relations in JSON (W3C).
- Hydra - Vocabulary for Hypermedia-Driven Web APIs (W3C).
- Schema.org - Collection of schemas describing common data models.